Speaking outside the court on Monday, Mrs Wragg said she was shocked by the sentence given to her ex-husband.

"It has been extremely difficult to sit and listen as the dignity of my little boy has been destroyed in an effort to reduce the impact of his death," she said.

"Jacob's condition has been used as an excuse for this crime and I find it appalling that anyone would try to portray him as being less deserving of his life, or less entitled to enjoy every precious moment his condition allowed.

"There are many sensitive issues raised by this tragedy which I know have affected other families, but I just need to say, as Jacob's mother, how proud I am to have loved and cared for such a spirited, happy and unique individual.

"I would like to thank the police and prosecution for their hard work and commitment on Jacob's behalf in securing a conviction - however I am shocked by the sentence and the message it sends to others."

Jacob was left deaf by the degenerative disease

Wragg's father Bob said: "We're very pleased with the sentence and all the sympathy shown by the judge.

"We would like to thank, on behalf of Andy, his legal team and all those who have supported us through these sad times.

"We now would ask that we be at last allowed to grieve the loss of Jacob who we all loved dearly."

Mr Wragg added that his son was "fine", but would not be making any statement himself.

The prosecution had argued Jacob's death was a "selfish killing" carried out because Wragg could no longer cope with looking after the boy.

Philip Katz QC, in his opening speech of the 10-day trial, said that while Wragg may have been feeling "disappointment, sadness, loss, fear and anger", he was not suffering from an abnormality of mind which would "substantially impair his mental responsibility for his actions".

But Wragg told police his son had wanted him to end his life and the jury accepted his plea of manslaughter.

Commenting on the outcome, Detective Chief Inspector Steve Johns, of Sussex Police, said it had been a sad and difficult case.

"Our sympathies go to Jacob's family and friends at this time," he said.